The purpose of the proposed SBIR Phase II project is to complete the development and testing of a computer- based HIV/AIDS prevention tool called Know the Risks: HIV Over 50 (KTR/50). The tool will provide critically needed HIV prevention and sexual health education resources to older adults, and encourage health provider recognition of this at-risk, but underserved, population, and facilitate increased levels of HIV/AIDS risk screening. The intended audiences for KTR/50 are adults 50 and older, and health care professionals who serve them in diverse settings, including medical, clinic, and adult residential settings. The tool is also being designed for use as a stand-alone tool that can be used in locations such as senior centers. KTR/50 includes two key features: 1) an audio-enhanced, automatic progressing HIV/AIDS Risk Screener;and 2) an interactive, multimedia HIV/AIDS Learning Activities Center offering sexual health information topics for those over age 50. Upon completing the risk screener, users will receive a customized HIV Risk Screening profile that they can discuss with their health provider. Phase II objectives include: 1) an instrument validation study of the modified risk screener selected in Phase I, conducted with adults over 50;2) revision of the KTR/50 prototype based on Phase I usability testing data;3) research, design and development of the remaining 10 of 12 Learning Center activities;4) extensive programming of all application features completed in Phase II;5) Scientific Panel review of an alpha version of the application;6) usability testing of a beta version of the application;and 7) field testing of the tool in five sites serving older adults. Statement of Relevance to Public Health The proposed SBIR Phase II project, Know the Risks: HIV Over 50 (KTR/50) will result in the development of a computer based HIV/AIDS screening and prevention education tool designed specifically for older adults, an underserved population in the HIV/AIDS epidemic. The tool will also facilitate health provider recognition of older adults'HIV risks, and support increased levels of HIV/AIDS risk screening.